/**
 * Express Middleware for lazy-render-server
 */

import { Request, Response, NextFunction } from 'express';
import { validatePaginationParams, calculatePagination } from './index';

declare global {
  namespace Express {
    interface Request {
      pagination?: {
        page: number;
        limit: number;
        cursor?: string;
        sortBy?: string;
        sortOrder?: 'asc' | 'desc';
      };
    }
  }
}

/**
 * Express middleware for pagination
 */
export function paginationMiddleware(
  req: Request,
  res: Response,
  next: NextFunction
) {
  const { page, limit, cursor, sortBy, sortOrder } = req.query;
  
  const validated = validatePaginationParams({
    page: parseInt(String(page)) || 1,
    limit: parseInt(String(limit)) || 50,
    cursor: String(cursor),
    sortBy: String(sortBy),
    sortOrder: sortOrder as 'asc' | 'desc'
  });
  
  if (validated.errors.length > 0) {
    return res.status(400).json({
      error: 'Invalid pagination parameters',
      details: validated.errors
    });
  }
  
  req.pagination = {
    page: validated.page,
    limit: validated.limit,
    cursor: validated.cursor,
    sortBy: validated.sortBy,
    sortOrder: validated.sortOrder
  };
  
  next();
}

/**
 * Error handler for pagination errors
 */
export function paginationErrorHandler(
  err: any,
  req: Request,
  res: Response,
  next: NextFunction
) {
  if (err.type === 'pagination_error') {
    return res.status(400).json({
      error: 'Pagination Error',
      message: err.message
    });
  }
  next(err);
}

export default {
  paginationMiddleware,
  paginationErrorHandler
};